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New Member

Another ISDN backup issue with MPPP

I am using channels in a channelized E1 to configure MPPP. Each MPPP goes to a different location. ISDN PRI is configured using dialer maps to provide backup in case MPPP fails.

When I administratively shut down one MPPP then according to static floating routes a channel in ISDN PRI is dialed. The problem is, when i no shut the same MPPP then it remains in down state and because of this ISDN never disconnets. To bring MPPP up I have to manually shut down ISDN dialer.

I am using dialer maps, OSPF and floating routes for backup.

Is it a known behavior or am I missing something :-/

I apologize but unfortunately at this moment I can not provide a config.

New Member

Re: Another ISDN backup issue with MPPP

Dialer-watch might be able to help you.Use dialer-watch instead of floating route.Dialer-watch can watch for a route and when this route disappears from your routing table the PRI will be dialed. When your main link is brought up the PRI will be disconnected by the dialer watch.

Do readup on Dialer-watch and ensure that it can satisfy all your requirements before you implement it on production.

Hope this helps. Do inform if this helped.

New Member

Re: Another ISDN backup issue with MPPP

Thanks for the information.

But the problem is somewhat different. There is no problem in failing over to backup isdn.

The problem is that the primary interface (MPPP Channelized E1) stays in down state till the time ISDN is active. Manually doing no shut on primary doesn't bring the link in up state. I have to manually disconnect ISDN call to bring the primary interface up.

Re: Another ISDN backup issue with MPPP


Is it possible for u to configure different dialers to different locations so that you can key in backup interface and backup delay commands under ur serial interface ?

That can also help u out in getting out of this probs.

But is it also possible to post out ur configs here ?


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